Machine for molding concrete



March 24, 1953 M. E. LEEUWRIK 2,632,224

MACHINE FOR MOLDING CONCRETE Filed NOV. 5, 1950 1 Ian: 24.350K X INVENTOR. ME. LEEUWRHK W, Lmd PM Pmoa msys Patented Mar. 24, 1953 UNITED STATES TET OFFICE MACHINE FOR MOLDING CONCRETE Application November 3, 1950, Serial No. 193,885

1 Claim.

One object of this invention is to provide an improved machine for producing concrete parts or articles by applyin a shaking operation.

As a result of the experiences and experiments of years it has been found that these objects can only be realized if precise directionswhich must be fulfilled simultaneously-are complied with.

In accordance with the above invention is characterized by the fact that the surface of the table upon which the mold for the article should be immovably fastened, is larger than the face determined by the outer perimeter of the mold which does not project beyond the edge of the table, that the contact surface of the anvils or stoprails ranges between 2 and 5 per cent of the surface of the table, that the weight (X) of the article to be made inclusive of the weight of the mold bears a definite proportion to the weight (Y) of the table inclusive of all parts secured to and dropping along with said table, which proportion is determined by the equation:

Y=0.18 (X+3.l9) 1.14

that the height of lift of the table ranges between M and that the frequency of the jolts ranges between 150 and 300 per minute, that the mold is so filled that a fresh layer of mortar is put in the mold only after the layer already present therein has been subjected to a shaking operation which has been continued until all air has disappeared from the said layer and the surface of said layer gleams owing to the water liberated from the concrete mortar.

A machine according to the invention is characterized by the fact that the face determined by the outer perimeter of the mold which does not project beyond the edge of the table, that the contact surface of the anvils or stoprails ranges between 2 and 5 per cent of the surface of the table, that the weight (X) of the article to be made inclusive of the weight of the mold bears a definite proportion to the weight (Y) of the table inclusive of all arts secured to and dropping along with said table, which proportion is determined by the equation:

that the height of lift of the table ranges between and that the frequency of the jolts ranges between 150 and 300 per minute.

The invention is illustrated hereinafter with reference to the drawing.

Fig. 1 shows a graph representing the proportion 2 in which the weight X of the mold with the article 2, as well as the weight Y of the table i with the stop rails 3 and the securing champs H (see Figs. 2 and 3) have to satisfy. The values X and Y in this equation represent hundreds of kilos.

If the weight X=l00 kgs., the weight Y will be 202 kgs.

If the weight X=500 kgs., the weight Y will be 1090 kgs. and if the weight X=1000 kgs., the weight Y will be 3018 kgs.

From this it appears that as X increases in magnitude the value Y increases at a more than proportional rate.

The jolting machine shown in Figs. 2 and 3 comprises besides a table i with stop rails 3, a base which stops the fall of the table and thus produces the jolts.

This base consists of rails l attached to a plate 5. This whole is borne by a heavy concrete block 6.

Against the lower side of the table rollers 8 are rotatively secured. Eccentric-shaped rollers 9 supported in a bearing block it, are located underneath the rollers 8. When the rollers 9 are rotated they will lift the rollers 8 and thus the table i. The rollers 9 have a cam-shaped edge for that purpose. After this edge has passed underneath the rollers 8, the rollers 8 and the table suddenly drop down.

The rails 3 then bang on the rails 4.

The lift h of the table should range between 1/4 and 1/2- The contact surface of the rails 3 and 4 should range between 2 and 5 per cent of the surface of the table.

This upper surface of the table 1 should be larger than the upper surface of the mold 2. The filling of the mold with concrete '8 should be so effected that first a layer is put in the mold whereupon this is subjected to a shaking operation until water appears on top of this concrete, making it gleam. Only then a new layer of concrete may be put in the mold. The mold 2 is immovably secured to the table I by means of clamps H.

The shaking frequency should range between and 300 jolts per minute.

The equation mentioned above as an essential condition relates to a parabola.

I claim:

A machine for producing concrete parts and articles by applying a shaking action comprising a table, a mold secured on the top surface of said table, the top surface of said table being larger than the outer perimeter of the mold which does not project beyond the edge of the 3 table. a base member, stop rails secured to said table and said base member, the contact surface of said stop rails being between 2 and 5 per cent of the surface of the table, the weight of the article to be made including the weight of the mold being in a definite proportion to the weight of the table including all parts secured to and dropable with said table in accordance with the equation:

4 lift of the table ranging between 4 inch and inch and the frequency of the jolts ranging between 150 and 300 per minute.

MATTHIJS E. LEEUWRIK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,523,936 Easterday Jan. 20, 1925 ,193,847 Strong Mar. 19, 1940 

